Amorphous TiZrNbTaFe high entropy alloy coatings for enhanced osseointegration of orthopedic implants

With aging populations and rising injury rates, the demand for orthopedic implants has increased significantly. Surface modifications have been developed to enhance implant longevity by improving mechanical and physicochemical properties. In this work, the osseointegration performance of high entropy alloy (HEA) coatings was evaluated through in vivo bone implantation tests. Two TiZrNbTaFe HEA coatings were deposited on the commercial pure titanium (cp-Ti) rod using a high power impulse magnetron sputtering system. These coated implants were inserted into the distal femur of rats, and their integration was assessed through pull-out mechanical testing, histological analysis, and micro-computed tomography imaging. Compared to bare cp-Ti, HEA-coated implants noticeably enhanced collagen synthesis, mineralization, and bone-like tissue fixation at the implant interface. The HEA coating with higher Ti content exhibited a more pronounced improvement in osseointegration. Overall, the TiZrNbTaFe HEA coatings improved both the quality and quantity of regenerated bone, highlighting their strong potential for orthopedic implant applications.